120 CHAPTER 6 Thermal Management Techniques progresses as long as the improvement is above some threshold value and includes the following steps [209]: 1. 2. 3. 4. 5. The power vector resulting from the new placement is determined. The temperature profile of the 3-D stack is calculated. The new value of the thermal and overlap forces are evaluated. The matrices of the repulsive forces are updated. A new placement is generated. Once the algorithm converges to a final placement, a postprocessing step follows. During this step, the circuit blocks are positioned with- out any overlaps within the planes of the system. If one plane is packed, the remaining cells that are initially destined for this plane are positioned onto the adjacent planes. A similar process takes place in the y-direction to align the circuit blocks into rows. A divide and conquer method is applied to avoid any overlaps within each row. A final sorting step in the x-direction includes a postprocessing proce- dure, after which no overlap among cells should exist.